Cod sursa(job #2384063)

Utilizator sebi212Sebi nechita sebi212 Data 20 martie 2019 10:29:44
Problema Dirichlet Scor 24
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.46 kb
#include<cstdio>
using namespace std;
#define MOD 9999991
long long fast_pow(int a,int b)
{
	long long aa=a,p;
	for(p=1;b; b=b>>1)
	{
		if(b&1)
		   p=(p*aa)%MOD;
		aa=(aa*aa)%MOD;
	}
	return p;
}
int main()
{
	freopen("dirichlet.in","r",stdin);
	freopen("dirichlet.out","w",stdout);
	int n,a,b,i;
	scanf("%d",&n);
	a=b=1;
	for(i=2;i<=n;i++)
	{
		a=a*(n+i)%MOD;
		b=b*i%MOD;
	}
	int af=a*(fast_pow(b,MOD-2))%MOD;
	printf("%d",af);
	return 0;
}